Method and system for fixing removable dentures

ABSTRACT

A removable denture system comprising a support beam fixedly attached to the individual&#39;s alveolar ridge above the mucous membrane by a plurality of dental implants, and a denture generally conforming with the dental parameters of the individual and integrated with a supper-structure. The supper-structure comprises at least a portion shaped in confirmation with the support beam, and a denture locking arrangement for removably though fixedly articulating the denture to the support beam preventing unintentional disengagement of the denture.

FIELD OF THE INVENTION

This invention generally relates to a method and a system for removableattachment of partial/full dentures (removable prosthesis) to an upperand a lower jaw of an individual such that the denture is attachable bya rigid and firm support construction.

BACKGROUND OF THE INVENTION

Partial or complete loss of an individual's natural teeth, either orboth at the upper and lower jaw, due to age, accident, diseases or otherreasons has some serious effects on an individual both functionally andsocially. Lack of teeth poses several serious functional problems suchas not being able to chew, speech difficulties, etc. Even more so, asmile with a full set of white teeth is considered something to bedesired, i.e. esthetics play an important role.

Utilization of a denture remains a problem. While dentures can beaccurately fitted to the alveolar ridge of an individual, it isdifficult to retain a denture in position. That is, during normalchewing or talking, the denture has a tendency to ride up out ofposition on the alveolar ridge, causing speech difficulties, chewingdifficulties, and general unsatisfactory use of a denture.

Since the denture is an artificial appliance fitted against livingtissue it is best to give that tissue a chance to rest without pressurefor some period each day. Many people also have the habit of clenchingtheir teeth when they sleep and this causes even more pressure againsttissue and bone in the mouth. It is thus recommended that dentures beremoved for some period of the day or night and treat the mouth and gumsand clean the dentures.

The denture is a removable dental prosthesis which has artificial teethembedded in a denture base resembling the gum or gingiva. The denturebase provides the support for the prosthesis by resting on the gingiva.The underside of the denture base has a depression receptacle thatreceives at least a portion of the gingiva so as to provide a snug,reversible fit of the denture onto the gingiva that was adjacent to thelost teeth.

A full denture is used for replacing an entire set of teeth. A fulldenture would replace the lower set of teeth (“lower denture”) or upperset of teeth (“upper denture”). With the full denture, the surface ofthe depression receptacle base adheres to the appropriate gingiva of thedenture wearer through saliva from the wearer's mouth causing a vacuumbetween the surface of the depression receptacle and the mucus membranesof the gingiva.

A bridge prosthesis is similar to that of a denture prosthesis exceptthe bridge is normally limited to being a partial denture which isnon-reversibly cemented or otherwise affixed to the adjacent teeth.

In recent years practice has developed of permanently implanting dentalimplants (at times referred to as dental fixtures or posts) in the bonestructure of the mouth. These permanent dental implants are usually madeof titanium which is more acceptable by the body's biological processesand which are locked into position by bone growth. By utilization of thepermanently installed implants in the mouth of the individual, thepossibility then exists for more readily securing a denture in placeeither fixedly or removably.

For example, U.S. Pat. No. 5,954,506 discloses a magnetic attachmentused for retaining a dental prosthesis, comprising a male part which maybe fixed to an abutment and a female part which may be fixed to thedental prosthesis. U.S. Pat. No. 5,997,300 discloses a stake anchored inthe base or root of the tooth, and a covering cup is mounted on thedenture. An engaging member is placed in the cup chamber, the engagingmember being a soft plastic annular member. When a ball head on thestake is engaged therein, the denture is fixed in place, the denture canalso be drawn out for removal, so that mounting and removal of thedenture at the area missing teeth is convenient.

According to some other particular arrangements, the denture is mountedon an anchor member, which In turn is permanently secured to theindividuals gum by means of permanently installed implants. The denture,according to several embodiments is detachable, and according to otherembodiments is fixedly attached to said anchor member.

U.S. Pat. No. 4,184,252 is concerned with an overdenture structure and amethod for securing it to the residual ridge of a patient. The nerve ofat least one healthy tooth is removed and the root canal is filled withdental paste as in a root canal treatment. The crown of the tooth isremoved near the gum line and a ferromagnetic bar is embedded in thefilled root. Magnetic material is embedded in the overdenture in suchposition as to be aligned with the ferromagnetic bar at closure points.The dental material surrounding the ferromagnetic bar and the magneticmaterial embedded in the overdenture are shaped so as to providecontoured mating surfaces with one another. In an alternativeembodiment, a root canal treatment is performed on two healthy teeth andbars are embedded in the roots of those teeth. A ferromagnetic rod isconnected between the ends of the two bars. Magnetic material isembedded in the overdenture in position to be aligned with the entirelength of the ferromagnetic rod. The dental material surrounding theferromagnetic bars and the magnetic material embedded in the overdentureare shaped so as to provide contoured mating surfaces with one another

U.S. Pat. No. 4,784,608 is concerned with an attachment for removablysupporting a denture in the mouth of the user in which the user has atleast two spaced apart dental implants implanted therein, the attachmentincluding a first basic portion in the form of an anchor membersemi-permanently attached to the anchor implant and being curved togenerally the shape of the alveolar ridge of the user and having a barportion extending between the spaced apart dental implants, the anchormember having retention means at the ends thereof such as in the form ofa recess at each end. The attachment second basic portion is a denturemember which conforms generally to the contour of the anchor member andwhich is engageable in proximity with the anchor member. The denturemember is cast within a denture having simulated gum portions and teethportions. The denture member has retention means such as integrallyformed implants which are removably insertable into the recess in theanchor member, the axis of the implants and the axis of the recessesbeing inclined toward planes of the anchor member and the denturemember. The denture member includes an arm pivotal between a locked andan unlocked position. The arm has a blade portion which engages theanchor member at a point intermediate the retention means so that thearm when in the locked position retains the denture within the mouth ofthe user, the arm being engagable at its outer end by the fingernail ofthe user so that it can be pivoted to the unlocked position, allowingthe denture to be removed.

U.S. Pat. No. 6,506,052 discloses a system of retrofitting non-dentalimplant secured dentures with dental implant technology in order to savetime and expenses to the denture wearer and to provide a marketingcapability that uses the benefits of retrofitted dentures ascommunicated to denture wearers to convince the denture wearers toreceive dental implants. The retrofitting of the said denture comprisesof modifying the depression receptacle of the denture base to accept aportion of the exposed part of at least one implant affixed to thedenture wearer and to accept a portion of the dental implant securingdevice. A portion of the dental implant securing device is affixed tothe depression receptacle so as to positioned dental implant securingdevice to reversible attach to at least a portion of the exposed art ofat least one implant affixed to the denture wearer when the denture isaffixed to the denture wearer.

Still another concept is at times referred to as the Novum™ system andis disclosed in the publication: ‘a new treatment concept forrehabilitation of the edentulous mandible. Preliminary results from aprospective clinical follow-up study’ [Clinical Implant DentistryRelated Res. 1999; 1(1):2-16; by Branemark P I, Engstrand P, Ohrnell LO, Grondahl K, Nilsson P, Hagberg K, Dark C, Lekholm U.]

The present invention provides a system and a method for fixedly thoughremovably supporting a denture in the mouth of an individual, whereinthe denture is rigidly secured but in a way so that it is easily andconveniently removed and reinstalled in the individual's mouth, at asturdy position.

SUMMARY OF THE INVENTION

According to the general aspects of the present invention there isprovided a removable denture system wherein the tolerance between asupport beam (often referred to in the art as a support bar or a lowerbar), fixedly mounted onto the individual's jaw bone and between asupper-structure (integrated within the removable denture) issubstantially tight, to thereby substantially eliminate any degrees offreedom therebetween, but only for removing of the denture. According tothe present invention a denture locking arrangement is provided forpreventing unintentional disengagement therebetween, and howeversubstantially not intended to bear any loads. By this it is meant thatthe locking system is substantially not subjected to mechanical loadssuch that all loads are born by the support beam, to be dispersed viathe implants to the jaw.

The support beam is fixedly applied to the individual's jaw by means ofa plurality of fixtures, and the denture is removably fixable over thesupport beam by means of a support structure integrated within thedenture, such that the denture is sturdily mounted over the supportbeam.

According to some particular embodiments of the present invention atleast an upper portion of the support beam (i.e. that portion which isremote from the jaw bone) has a near to rectangular cross-section, i.e.at least the side surfaces of which are substantially parallel to oneanother and optionally with a substantially flat top surface, therebygiving rise to a trapezoid section-like shape or, in some particularcases, the top surface is disposed at a right angle to the sidesurfaces, thereby giving rise to a rectangle section-like shape.

A corresponding cross-section of the support-structure of the denture,practically embraces the support beam, thereby eliminating, orsubstantially canceling any degrees of freedom therebetween, so as toreduce moments of force developing over dental implants/fixtures andfurther, such that a person fitted with a denture according to thepresent invention does not experience unpleasant and insecure feeling ofa denture moving in his mouth.

The support beam, according to one specific design, has a near torectangular cross-section, with an extracting angle (angle of the sidewalls) of about 4° to 12°, and more likely about 6°.

According to a particular embodiment of the invention the denturelocking arrangement comprises inwardly displaceable locking members(i.e. retractable in direction into the individual's mouth) and byspecific design, two locking pins laterally retractable inwardly, eachextending at or near a side portion of the denture (i.e. extendinglateral to the tongue), though medial (frontal) positioning is possibleas well, so as to cause minimal interruption and discomfort with thegingiva and tongue.

Readily removable locking of the denture to the support beam is carriedout by positive locking i.e. not of the type relying on friction,magnetic force, resilience snap, etc., but rather using locking pinsystems or swivel-type lock systems.

According to a first aspect of the invention, the individual's jaw bone(alveolar crest) is machined (leveled) to form a smooth surface ontowhich a lower bar is fixedly fitted by means of several fixtures(typically three). Then, a support beam is precisely positioned over thelower bar and is fixedly secured thereto, similar to what is proposed bythe Novum™ system. This structure provides a so called passive fit.Then, one or more locking studs (two were found to be perfect) are fixedto the support beam (e.g. by screwing). Typically, the locking studs arefixed at pre-selected retention bores formed in the support beam (whichare regularly used for fixedly fastening thereto a denture). Apersonalized denture formed with a support structure is then placed overthe support beam and is locked in position by locking members laterallyextendable for arresting the locking studs. In this manner, the dentureis steadily fixed over the support beam and is easily and readilyremovable.

According to a first embodiment of the present invention the supportstructure is an upper bar integrated within the denture, where a bottomsurface thereof is fitted for bearing in contact surface over a topsurface of the support beam (which in this particular application may bereferred to as a lower bar).

According to an other embodiment of the invention, the support structureis a supper-structure formed with a support-beam receptacle having aU-like cross-section, conforming with that of at least an upper portionof the support beam for snugly embracing it. In accordance with amodification of the second embodiment the support beam is fixedlyfitted, in a non-removable manner, with an upper-bar (giving rise to auniform support beam of increased height, where the support structure isa supper-structure formed with a support-beam receptacle having a U-likecross-section, conforming with that of at least an upper portion of theattached upper-bar, for snugly embracing it, though removably.

According to the first embodiment, the support structure is an upper barintegrated with the personalized denture, i.e. the denture is moldedover the upper bar with the locking members being retractable throughthe upper bar for locking engagement with locking studs projectingvertically from the support beam.

According to the second embodiment of the invention, the personalizeddenture is integrated with the supper-structure, fitted for snuglyreceiving the support beam, wherein the locking members are retractablethrough the supper-structure for locking engagement directly withsuitable bores formed in the support beam. The term snugly as usedherein refers to close contact between the supper-structure and thesupport beam, i.e. close/intimate surface contact over substantially theentire surface of the supper-structure.

Locking engagement between the locking members and the locking studs isfor example by a locking pin fitted for engagement with a busted boreformed in the locking stud or by engagement of said pin with aperipheral grove formed on the locking stud, for arresting the dentureto thereby prevent its unintentional removal. Preferably, axialdisplacement of the locking pins is restricted to thereby prevent theircomplete retraction.

According to another aspect of the present invention, an individual andpersonalized support beam is custom manufactured, tailored to theparticular anatomy of the individual (namely jaw structure andsituation), according to different parameters obtained e.g. byperiapical X-ray, panoramic X-ray, CT imaging, study models, etc. of theindividual. Accordingly, a personalized kit is prepared, whereby asupport beam and dental implants (fixtures) are provided along with afixture kit comprising positioning templates, pins, drills and mandrels,etc. The support beam is then fixedly attached to the individual's jawbone over the implants pre-implanted into the jaw (with or withoutleveling of the alveolar crest, and thereafter a personalized denture isremovably attached over the support beam in accordance with any of theembodiments disclosed hereinabove.

The term personalized denture as used hereinabove denotes a denturemimicking the individual's natural teeth and gums (i.e. color, shape,size and matching with the opposite jaw's teeth/denture, etc), typicallymade of acrylic material (at times with porcelain coating of theartificial teeth formed therein). It is highly desired that each dentureaccording to the present invention be fitted with a skirt (lateral andfrontal flange coverage) extending downwards to intimate close contactwith the vestibular area, i.e. over the at least a major portion of thegums. The skirt portion simulates and completes the gingival area andoffers an aesthetic appearance and to conceal any artificial structureon the one hand, and on the other hand to cover any gaps which normallywould exist so as to prevent phonetic disorders (mispronunciation) andsaliva and food escape.

Either of the methods above disclosed is suited for both the upper andlower jaws and any locking arrangement is suited for removably thoughfixedly attaching the denture to the fixed support beam. Furthermore,where the locking members are inwardly retractable pins, there may beformed a narrow bore at the front face of the denture through which anaid may be applied to assist in retraction of the locking pins.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to better understand the invention and to see how it may becarried out in practice, some embodiments will now be described, by wayof non-limiting examples only, with reference to the accompanyingdrawings, in which:

FIGS. 1A through 1F sequentially illustrate steps for installing aprefabricated precision support structure in an individual's lower jaw;

FIG. 2A is an isometric exploded view of the components of theprefabricated precision components;

FIG. 2B illustrates a step of permanently fixing a lower bar to theindividual's jaw;

FIG. 2C the description of which is a sectional view along line II-II ofthe support bar seen in FIG. 2A;

FIG. 3 is a front view of a lower jaw fitted with a prefabricatedsupport system in accordance with a prior art method;

FIG. 4A is a top isometric view from an inside of a denture inaccordance with the present invention;

FIG. 4B is a bottom view of the denture as seen in FIG. 4A;

FIGS. 5A and 5B are cross-sectional views along lines IV and V in FIGS.4A and 4B, respectively, illustrating a locking mechanism in accordancewith one particular embodiment in accordance with the present invention;

FIG. 6 is a sectioned exploded view of a denture and support beam fixedto a lower jaw, in accordance with an embodiment of the presentinvention;

FIG. 7 is a longitudinal section illustrating a removable denture inaccordance with an embodiment of the present invention, removably fittedover an individual's jaw;

FIG. 8A illustrates positioning and locking of a denture in accordancewith an embodiment of the present invention;

FIG. 8B illustrates a denture in accordance with an embodiment of thepresent invention fitted in an individual's mouth;

FIGS. 9A through 9H illustrate sequential steps of preparing and fittinga support beam to be used in accordance with a different embodiment ofits present invention;

FIG. 10 is a longitudinal section illustrating how a denture is fittedon a support beam in accordance with a different embodiment of thepresent invention;

FIG. 11A is a sectioned exploded view of a denture and support beamfixed to a lower jaw, in accordance with another embodiment of thepresent invention; and

FIG. 11B is a longitudinal section illustrating the denture inaccordance with the embodiment of FIG. 11A, removably fitted over anindividual's jaw.

DETAILED DESCRIPTION OF SPECIFIC EMBODIMENTS

Attention is first directed to FIGS. 1A through 1F and to 2A and 2Bsequentially illustrating a surgical protocol for fitting a rigiddenture support beam generally designated 10 (FIG. 2A). Afterpreoperative radiographic examination for determining thecharacteristics of the jaw bone 12 (low jaw bone in the present example)the individual is anesthetized and a crestal incision is made to exposethe jaw bone by incising mucosa 13 (small window in FIG. 1A). Then, thecrestal jaw bone in the anterior region is reduced using a rimmer 14 soas to obtain a wide bone platform 16 suitable for accommodating aprefabricated titanium template (18 in FIG. 1D). Several differenttemplates are used during the drilling procedure for graduallyincreasing the diameter of the preparations made with speciallydesignated drills 20. A first template used is a so-called guidetemplate setting the position of the sites (for the implants) beginningwith marking a central fixture position with a standard round bore 24(FIG. 1B) the marked position was then enlarged using a twist drill (28in the small window of FIG. 1B). A guide pin 30 (FIG. 1C) is then placedthrough the guide template 18 and two additional fixture sites 34A and34B are marked. The evaluation template 18 is then replaced bypositioning templates 18B through 18E using suitable drill guides (38 inFIG. 1D) to gradually increase the dimension of the central fixtureposition and then, as seen in FIG. 1E, a fixture 42 is inserted throughthe template 18D. The two side sites earlier marked as 34A and 34B arethen drilled (FIG. 1E) and their dimension is enlarged (small window inFIG. 1F) to facilitate insertion of two side fixtures 44 and 46.

Then, using a set of titanium screws 50 (FIG. 2B), a lower bar 54 isfixedly secured to the fixtures 42, 44 and 46 in a permanent fashion.

Optionally, a thin silicon support sheet 58 (FIGS. 2B and 3) is placedon the mucosa 13 surrounding the implants 42, 44 and 46 to therebycounteract edema and seal the incision formed during the procedure. Itis seen in FIGS. 2A, 2B and 3 that the lower bar 54 has a flat topsurface 60 preformed with several threaded bores 64. Placed on the lowerbar 54 there is a upper bar generally designated 70 (FIGS. 2A and 3)made of titanium and by means of screws 74 is fixedly attached inabutting engagement to the lower bar 54 such that the lower surface 78of the support bar upper bar 70 bears flush against the upper surface 60of the lower bar 54 as can best be seen in FIG. 3, giving rise to arigidly integrated assembly of the support beam 10. Screws 74 fit intoprefabricated bores 76 positioned in coaxial alignment with threadedbores 64 in the lower bar 54.

In FIG. 2C there is illustrated a section taken at the center of supportstructure generally designated 10 illustrating a bottom surface 78 ofthe upper bar 70 which is substantially flat and smooth for flushabutting against the top surface 60 of the lower bar 54 and further,comprises upper side surfaces 80 substantially of rectangularcross-section and which form an extracting angle of about 4° to 12° andmore likely about 6°, with chamfered top edges at 81, and asubstantially flat top surface at 83.

The upper bar 70 of the support beam 10 is formed with two precise,laterally extending, through-going, apertures 83 (FIGS. 2A and 3) whichapertures constitute part of the denture locking mechanism for removablythough fixedly mounting a denture thereto, as will become apparenthereinafter.

It is appreciated that the above description follows, at leastpartially, the so-called Brånemark Novum® procedure for example asillustrated in the literature. This system however, provides a supportconstruction for use in conjunction with a denture in accordance withthe present invention and constitutes part of the system.

Turning now to FIGS. 4A and 4B there is shown a denture generallydesignated 100 made of an acrylic material and integrally fitted with aplurality of teeth 111 mimicking the individual's natural teeth as faras shape, size, color, etc. and further comprising a gum mimickingportion (skirt) comprising a front gum portion 104 and a rear gumportion 106, the color and texture of which mimicking the naturalappearance of the individual's gum. The skirt (lateral and frontalflange coverage) extends downwards to intimate close contact with thevestibular area, i.e. over the at least a major portion of the gums. Theskirt portion simulates and completes the gingival area and offers anaesthetic appearance and to conceal any artificial structure on the onehand, and on the other hand to cover any gaps which normally would existso as to prevent phonetic disorders (mispronunciation) and saliva andfood escape.

Integrated and fixedly received within the denture 100 there is asupport structure 110 (FIG. 4B) made of hard material e.g. metal, andhaving a U-like cross-section conforming with and fitted for snuglyreceiving and embracing at least the upper portion 80 of the upper bar70 of the support beam 10 such that the denture 100 is applied (placed)over the support beam 10 in a substantially vertical position andremoved in the same fashion and further, such that the tolerance betweenthe support beam 10 and the super structure 110 of the denture 100 issubstantially tight to thereby substantially eliminate any degrees offreedom therebetween (apart for allowing removal of the denture asmentioned hereinbefore).

This arrangement has significant importance in long-life of the denturesupport system as minimal moments of inertia develop in the system andin the fixtures. Of further importance is the fact that in an individualfitted with a system in accordance with the present inventionsubstantially does not experience the unpleasant feeling of denturesmoving in the mouth.

As can further be seen in FIGS. 4A and 4B the denture 100 is fitted withtwo locks 112 being pin-snapped type locks as can be seen in more detailin FIGS. 5A and 5B. The locks 112 comprise a housing 116 rigidlyembedded within the denture 100, said housing being in the form of afitted with a sleeve 118 typically made of elastomeric or ceramicmaterial and furthermore, comprising a locking pin 120 formed with anannular displacement limiting ring 122 for snapping arrestments by saidsleeve 118 between a locked position (FIGS. 4B and 5B respectively) andthen an open position (FIGS. 4A and 5A respectively). The locking pin120 is further fitted with a head 126 which in the locked position issubstantially flush with the surface of the inner gum mimicking skirtportion 106 for maximum comfort of the individual though optionaly thereexists a small interstice 130 (FIGS. 4B and 5B) to facilitate extractingthe locking pin by the individual's fingernail, for example. Thearrangement is such that locking pin 120 is fitted for snugly fittingwithin bores 83 formed in the upper bar 70 of the assembled support beam10.

Whilst one particular locking mechanism has been illustrated, it isappreciated that other forms of locking arrangements may be applied aswell, e.g. the so-called swivel-type lock mechanism (not shown).

According to a modification of the invention, where it is required toprovide more rigidity to the connecting arrangement between the denture100 and the support structure, the support beam 70 may be fitted withseveral locking studs in the form of vertically projecting pins 140(FIG. 2A) fitted with an annular groove 142. In use, the studs 140project into pre-formed apertures 146 formed in the super structure 110of the denture 100, where said locking pin 120 is fitted for arrestingand engagement with the peripheral grooves 142 to prevent displacement(unintentional removal) of the denture 100.

It is appreciated that the locking mechanism provided substantially doesnot serve for bearing any loads but rather to prevent unintentionalremoval of the denture. It is further noticed that the locking mechanism112 is fitted at an inside surface of the gum mimicking skirt portionlateral to the tongue, so as to cause minimum disturbance and unpleasantfeeling, and also to provide an aesthetic appearance. However, at times,one or more locking mechanisms may be fitted at a frontal position (notshown).

In order to facilitate easy extraction of the locking pin, the denture110 may be fitted with a two through going bores 150 (FIG. 8B) barelynoticeable, only upon retracting the individual's lower lip 152, wherebya thin article may be introduced so as to push against the end of thelocking pin 120 to facilitate its retraction.

It is further noticed in FIG. 8B that the front skirt of the gummimicking portion 104 extends downwardly so as to merge with the naturalgum of the individual and to substantially conceal all the supportstructure. This has both an aesthetic meaning and also serves to coverany gaps which normally would exist to thereby prevent phoneticdisorders (mispronunciation) and saliva and food escape through suchgaps which may obviously cause some unpleasant incidents.

As already mentioned above, and as can further be seen in FIG. 6, thedenture system in accordance with the present invention is designed suchthat the denture 100 is fitted on the support beam and removedtherefrom, merely in a upright (vertical) displacement, i.e. alongarrowed line 160 in FIG. 6, however without deteriorating the rigid andsturdy support of the denture 100 over the support beam 70 this owing tothe snug fit of the super structure 110 over at least the upper,rectangle portion 80 of the support beam 10. This can clearly be seen inthe sectioned illustration of FIG. 7.

Further attention is now directed to FIGS. 9A through 9H and FIG. 10illustrating a denture assembly in accordance with still a differentembodiment of the present invention and a method for its manufacture. Inaccordance with this embodiment, an individual and personalized supportbeam 180 is custom manufactured, tailored in accordance with theparticular physiology of the individual. This is obtained by firstpreparing an imprint (model) of the individual's jaw, and then afterobtaining further anatomic information, e.g. jaw structure, situation ofjaw bone, etc., obtained from CT imaging (FIG. 9A), panoramic X-ray,periapical X-ray, study models, etc. implants are implanted into theimprint at the most appropriate locations and positions, in compliancewith the anatomy of the individual and based on said information. Then,a second imprint is prepared which includes the precise location andposition of the implants. Based on that second imprint, a computer aidedmanufacture system takes place (FIG. 9B) to manufacture a high accuracysupport beam 180 (FIGS. 9C-9E) formed with prepositioned bores 186 forfixedly connecting to fixtures 190 to be positioned in the individual'sjaw (FIGS. 9F-9H) depending on the parameters obtained as mentionedhereinabove. Simultaneously, a denture 191 (seen in section in FIG. 10)is manufactured similar to the arrangement disclosed in FIGS. 4A and 4B,with an integrated U-sectioned super-structure 192 intended for snuglyfitting over the support beam 180. The support beam 180 is machined intoits final form as seen in FIGS. 9G and 9H formed with an upper portion194 having a substantially rectangular cross-section. Thereafter, thesupport beam 180 is fixedly attached to the fixtures 190 by means ofscrews 196 (position seen in FIGS. 9G and 9H) eliminating the lower bardiscussed in connection with the previous embodiments.

The denture 191 is mounted on the support beam 180 in the same fashionas disclosed in connection with the previous embodiment and as discussedfor example in connection with FIG. 6, namely substantial verticaldisplacement, whereby locking engagement of the denture 191 with thesupport beam 180 is facilitated with a locking mechanism of any type(not seen), e.g. as disclosed in connection with the particular snap-pinlock type discussed in FIGS. 5A and 5B.

With further reference now being made to FIGS. 11A and 11B, there isillustrated still another embodiment according to the present invention,wherein the support beam 200 is fixed over implants 202 to jaw 204 of anindividual, said support beam 200 being in the form of a so-called lowerbeam, namely having a flat and smooth top surface 208. Integrated andfixedly received within the denture 210 there is a support structure 214(which resembles a so-called upper bar). The support structure 214 ismade of hard material e.g. metal, and having a smooth and flat bottomsurface 216 conforming with and fitted for flush bearing over the topsurface 208 of the support beam 200.

The denture 210 is fitted with a gum-mimicking skirt as discussed inconnection with the previous embodiments and further comprises twopin-snap type locks 220 and the support beam 200 is formed withcorresponding lock-receptacles 222 for lockingly arresting the locks220, e.g. of the type discussed herein above in connection with FIGS. 5Aand 5B.

The arrangement in accordance with this embodiment is such that thedenture 210 is applied over the support beam 200 (FIG. 11B) such thatthe bottom surface 216 of the support structure 214 (upper bar) bears infull contact surface over the top surface 208 of the support beam 200(lower bar).

The arrangement is such that the denture 210 is placed over and removedfrom the support beam 200 in a substantially vertical manner, whereby atthe assembled position of FIG. 11B and removed in the same fashion andfurther, upon locking the locks 220 any degrees of freedom therebetweenare substantially eliminated.

Whilst some embodiments have been described and illustrated withreference to some drawings, the artisan will appreciate that manyvariations are possible which do not depart from the general scope ofthe invention, mutatis, mutandis. For example, different lockingmechanisms may be applied to ensure locking engagement between thedenture and the support member. It is further appreciated that thehereinabove described systems and methods may be applied to the top andbottom jaw, though special care should be taken to fit an appropriatesupport structure to the particular anatomic parameters and features ofthe individual.

1-46. (canceled)
 47. A removable denture system comprising: apersonalized support beam in a form of a lower bar configured for beingfixedly attached to an individual's alveolar ridge above the mucousmembrane by a plurality of dental implants; a personalized denturegenerally conforming with the dental parameters of the individual andbeing fixedly integrated with a super-structure having a flat lowersurface along the entire length thereof and being made of metal, saidflat lower surface shaped in conformation with the lower bar; and adenture locking arrangement for articulating the denture to the lowerbar preventing unintentional disengagement of the denture and allowingits removal by the individual, wherein the lower surface of thesuper-structure bears in substantially full surface contact over the topsurface of the lower bar.
 48. A removable denture system according toclaim 47, wherein the super structure is formed with apertures and thelower bar comprises pins adapted to be received within said apertures inthe super-structure.
 49. A removable denture system according to claim47, wherein the super-structure has a substantially rectangularcross-section conforming with that of the lower bar, to therebysubstantially eliminate any degrees of freedom therebetween.
 50. Aremovable denture system according to claim 47, wherein the denture hasan indented portion for entering a fingernail behind the head of thelocking pin, to facilitate extraction of the locking pin.
 51. Aremovable denture system according to claim 47, wherein locking studsare fixed at pre-selected retention bores formed in the lower bar, whichbores are regularly used for fixedly fastening thereto a denture.
 52. Aremovable denture system according to claim 47, wherein the denturelocking arrangement comprises a bore at a front face of the denture,coextending with a locking pin of the locking mechanism, to facilitateextraction thereof and removal of the denture.
 53. A removable denturesystem comprising: a personalized support beam in a form of a lower barfixedly attached to the individual's alveolar ridge above the mucousmembrane by a plurality of dental implants; a personalized denturegenerally conforming with the dental parameters of the individual andbeing fixedly integrated with a super-structure being made of metal,said super-structure shaped in conformation with at least said lower barof the support beam and having a flat lower surface along the entirelength thereof, the super-structure bearing in substantially fullsurface contact over the top surface of the lower bar; and a denturelocking arrangement for removably though fixedly articulating thedenture to the lower bar preventing unintentional disengagement of thedenture.
 54. A removable denture system according to claim 53, whereinthe super-structure has a cross section conforming at least with anupper portion of the lower bar for snugly embracing thereof.
 55. Aremovable denture according to claim 54, wherein the superstructurecircumferences three faces of the lower bar.
 56. A removable denturesystem according to claim 54, wherein the rectangular cross-section ofthe support beam is formed with an extracting angle in the range of 0°to 12° on one or both side faces thereof.
 57. A removable denture systemaccording to claim 54, wherein the super-structure has a substantiallyrectangular cross-section conforming with that of the lower bar, tothereby substantially eliminate any degrees of freedom therebetween. 58.A removable denture system according to claim 53, wherein at anassembled position the locking arrangement substantially does not bearany loads.
 59. A removable denture system according to claim 56, whereinmoments of force over dental implants are substantially reduced oreliminated.
 60. A removable denture system according to claim 53,wherein the denture locking arrangement comprises one or more lockingmembers extending at an inside or outside face of the denture andadapted for locking engagement with a corresponding locking portion ofthe lower bar.
 61. A removable denture system according to claim 53,wherein the denture locking arrangement comprises a bore at a front faceof the denture, coextending with a locking pin of the locking mechanism,to facilitate extraction thereof and removal of the denture.
 62. Amethod for removably securing a denture to an individual, the methodcomprising the following steps: fixedly attaching a personalized supportbeam in a form of a lower bar to the individual's jaw bone; providing apersonalized denture being fixedly integrated with a super-structurebeing made of metal formed with a cross-section corresponding to thelower bar, said super-structure having a flat lower surface along theentire length thereof, the super-structure bearing in full surfacecontact over the top surface of the lower bar, and formed with a lockingmechanism comprising one or more locking members extending at an insideor outside face of the denture and adapted for locking engagement with acorresponding locking portion of the lower bar; and fitting the denturesnugly over said lower bar and locking it by the locking mechanism. 63.A method according to claim 62, wherein the cross-section of the lowerbar has a substantially rectangular cross-section.
 64. A methodaccording to claim 62, wherein the rectangular section of the lower baris formed with an extracting angle in the range of 0° to 12° on one orboth faces thereof.
 65. A method according to claim 62, wherein thesuper-structure has a substantially rectangular cross-section conformingwith that of the lower bar, to thereby substantially eliminate anydegrees of freedom therebetween.
 66. A method according to claim 63,wherein the locking mechanism substantially does not bear any loads. 67.A method according to claim 63, wherein degrees of freedom between thelower bar and the denture are eliminated or substantially canceled. 68.A method according to claim 63, wherein moments of force over dentalimplants are substantially reduced or eliminated.
 69. A method accordingto claim 63, wherein the denture is fitted for substantially verticalmounting over the support beam and detaching therefrom.
 70. A removabledenture system comprising: a support beam in a form of a lower baradapted for being fixedly attached to an individual's alveolar ridgeabove the mucous membrane by a plurality of dental implants; a denturegenerally conforming with the dental parameters of the individual andintegrated with a super-structure having a near-to-rectangularcross-section along the entire length thereof and being made of metal,said U-like cross section shaped in conformation with the lower bar; anda denture locking arrangement for articulating the denture to the lowerbar preventing unintentional disengagement of the denture and allowingits removal by the individual, wherein the super-structure snuglyembraces and contacts the lower bar with a tight clearance oversubstantially the entire surface of the lower bar.
 71. A removabledenture system comprising: a support beam in a form of a lower baradapted for being fixedly attached to an individual's alveolar ridgeabove the mucous membrane by a plurality of dental implants; a denturegenerally conforming with the dental parameters of the individual andintegrated with a super-structure having a flat lower surfacecross-section along the entire length thereof and being made of metal,said U-like cross section shaped in conformation with the lower bar; anda denture locking arrangement for articulating the denture to the lowerbar preventing unintentional disengagement of the denture and allowingits removal by the individual, wherein the super-structure snuglyembraces and contacts the lower bar with a tight clearance oversubstantially the entire surface of the lower bar.
 72. A removabledenture system comprising: a support beam in a form of a lower baradapted for being fixedly attached to an individual's alveolar ridgeabove the mucous membrane by a plurality of dental implants; a denturegenerally conforming with the dental parameters of the individual andintegrated with a super-structure having a U-like cross-section andbeing made of metal, said U-like cross section shaped in conformationwith the lower bar; and a denture locking arrangement for articulatingthe denture to the lower bar preventing unintentional disengagement ofthe denture and allowing its removal by the individual, wherein thebottom surface of the super-structure bears in full contact surface overthe top surface of the lower bar over substantially the entire surfaceof the lower bar.
 73. A removable denture system comprising: a supportbeam in a form of a lower bar adapted for being fixedly attached to anindividual's alveolar ridge above the mucous membrane by a plurality ofdental implants; a denture generally conforming with the dentalparameters of the individual and integrated with a super-structurehaving a U-like cross-section and being made of metal, said U-like crosssection shaped in conformation with the lower bar; and a denture lockingarrangement for articulating the denture to the lower bar preventingunintentional disengagement of the denture and allowing its removal bythe individual, wherein walls of the super-structure practically embracethe lower bar with a tight clearance over substantially the entiresurface of the lower bar.
 74. A removable denture system comprising: asupport beam in a form of a lower bar adapted for being fixedly attachedto an individual's alveolar ridge above the mucous membrane by aplurality of dental implants; a denture generally conforming with thedental parameters of the individual and integrated with asuper-structure having a U-like cross-section and being made of metal,said U-like cross section shaped in conformation with the lower bar; anda denture locking arrangement for articulating the denture to the lowerbar preventing unintentional disengagement of the denture and allowingits removal by the individual, wherein walls of the super-structure havea length less than the walls of the lower bar the lower bar with a tightclearance over substantially the entire surface of the lower bar.